If you mean the West Coast, it was the 9th Circuit court ruling in Martin v. Boise that brought about the visible camping. That ruling states that a city can’t

If you mean the West Coast, it was the 9th Circuit court ruling in Martin v. Boise that brought about the visible camping. That ruling states that a city can’t penalize someone for sleeping in public if they can’t provide a meaningful alternative. Most West Coast cities don’t have nearly enough shelter space available, and they have interpreted the ruling to mean that they cannot enforce camping bans at all - presumably to reduce the risk of being sued.